1. Field of the Invention
The subject invention relates to a high intensity laser beam delivery system, a beam expander for use in a high intensity laser beam delivery system and a method for expanding the beam diameter of a high intensity beam.
2. Background and Related Art
High intensity laser beams are now in use in the art. Such beams include UV beam such as third and fourth harmonic of Nd:YAG, Nd:YVO4 and Nd:YLF UV beams. See U.S. Pat. Nos. 5,898,717 (YIN) and 6,061,370 (YIN). High intensity beams particular UV beams can damage the coatings, lenses and mirrors used to direct and focus the high intensity beam to a desired location or work surface.
Beam expanders have been used in the art for a variety of purposes. For example, beam expanders have been used to increase the beam diameter of a high intensity beam to reduce damage to system components. They have also been used to expand the beam so it can then be focused to smaller spot size. However, such prior art beam expanders have been susceptible to damage by the high intensity beam and have resulted in diminished longevity of the high intensity laser beam delivery system. There is a need for high intensity laser beam delivery systems, which have a long life and which can deliver an expanded high intensity beam.